How often do you change RODI filters

[West1]

i find my di needs to be changed about every 3 months. if tds is not zero, it gets changed. one caveat. membrane life can be greatly increased by regular backwashing of the membrane. i use the aquatic life smart buddy booster pump with my filter. not only boosts pressure for better yield but does an 18 second backwash every time it starts up.

gary

awesome, What grade/cartridge are you using?
I have a spectrapure di unit and just ran the stock filters it came with. Im not sure which carbon, sediment, di to buy for best bang for my buck.

 

[cromag27]

I have never heard of this. Is there a standard procedure for this or a link you can provide?
Thanks.

http://reef2reef.com/threads/did-i-ruin-my-filter.117823/#post-1324928

 

[cromag27]

awesome, What grade/cartridge are you using?
I have a spectrapure di unit and just ran the stock filters it came with. Im not sure which carbon, sediment, di to buy for best bang for my buck.

Which rodi unit do you have?

 

[Michael E.]

As with most people in the thread...I change sediment and carbon religiously every 6 months. I keep a few backups that have dates marked on them when to change. I use spectrapures RODI system. Havent had any drop with the RO membrane, and both DI cartridges are looking good. The system is about a year old.

 

[West1]

Which rodi unit do you have?

I purchased the Starter Kit RoDI that came with small handheld TDS meter and Chlorine test kit (capsules).

 

[cromag27]

I purchased the Starter Kit RoDI that came with small handheld TDS meter and Chlorine test kit (capsules).

They make a few different rodi units. some have two di resins, some have one. in any case, I would suggest the .5 sediment, .5 carbon, enduro di and mega maxcap.

 

[West1]

I only have one di. I will try the .5 sed, .5 carb and the 43.00 Maxcap, tyvm!
The ones that came with the unit only lasted me about 120.00 gls (filled 40gl Rubbermaid three times). DI is reading 1ppm

 

[TaylorPilot]

They make a few different rodi units. some have two di resins, some have one. in any case, I would suggest the .5 sediment, .5 carbon, enduro di and mega maxcap.

Yea, I am learning fast that cheap sediment filters really screw you up. Their 0.2 micron ones are amazing and make the carbon blocks last forever....

 

[cromag27]

Yea, I am learning fast that cheap sediment filters really screw you up. Their 0.2 micron ones are amazing and make the carbon blocks last forever....

Yup! not all rodi filters are created equal.

 

[jwshiver]

http://reef2reef.com/threads/did-i-ruin-my-filter.117823/#post-1324928

THANKS!

 

[eubear]

Get BRS total chlorine test strips. When you start detecting more chlorine in the waste water it's time to change the carbon. When pressure drops to your RO from normal, change sediment. Change the DI when your TDS rises in the good water. RO membranes should last you many years if you maintain it, flush them, and keep chlorine away from them because it will oxidize them.

 

[eubear]

is there an easy way to flush your RODI system?

 

[Dvanlier05]

I like having the peace of mind knowing my water is pristine so I change my sediment and carbon blocks every month to two months, RO membrane is every year, and DIs when needed.

 

[cromag27]

I like having the peace of mind knowing my water is pristine so I change my sediment and carbon blocks every month to two months, RO membrane is every year, and DIs when needed.

you could be wasting money. see the rodi link in my signature.

 

[cromag27]

is there an easy way to flush your RODI system?

yes. see the rodi link in my signature.

 

[cromag27]

a fouled carbon filter can also drop pressure.

 

[Buckeye Hydro]

is there an easy way to flush your RODI system?

There is: https://www.buckeyehydro.com/membrane-flush-kit/

 

[Buckeye Hydro]

a fouled carbon filter can also drop pressure.

True, but...

About the only time you should see a carbon block clogged with sediment is if the pore sizes on the sediment filter and carbon block are not configured well. For example, there is a nationwide vendor of RO systems who has, for years (going back to the time of the previous owner), sold systems with prefilters like this:
10 mic sediment -> 5 mic carbon -> 1 mic carbon

This sort of set up is ill-advised, as the carbon blocks will act as sediment filters rather than being clean to do the task you bought them for. The concept of decreasing pore size on successive filters is a good one, but it applies to sediment filters only.

Russ

 

[BuddyBonButt]

My rodi unit is reading 2 and it's only been 3 months since I've started using it. I have an aqualife rodi unit. Let's say my resin is good. What else could be causing this issue.

My city does use chloramine instead of chlorine. I know chloramine is harsher on the membrane so if this is the issue what would I do?

Here's a cut/paste from our FAQ's section - you can access all of our FAQ's from our homepage:

A good rule of thumb is to replace your sediment filter and carbon block after six months. A more precise way to maximize the usable life of these two filters is to use a pressure gauge to identify when pressure reaching the membrane starts to decline. This is your indication one or more of the prefilters (all the filters that touch the water before it reaches the RO membrane) is beginning to clog.

Also be cognizant of the chlorine capacity of the carbon block. A good 0.5 micron carbon block for example will remove much of the chlorine from 20,000 gallons of tap water presented at 1 gpm. Some original equipment suppliers commonly provide carbon cartridges rated at 2,000 to 6,000 gallons. Remember that all the water you process, both waste water and purified water, goes through the carbon block. It's good practice to change the carbon block out at no more than 50% of the stated chlorine capacity.

Regarding your RO membrane and DI resin, use your total dissolved solids (TDS) meter to measure, record, and track the TDS (expressed in parts per million [ppm]) in three places: 1) tap water, 2) after the RO but before the DI, and 3) after the DI.

The TDS in your tap water will likely range from about 50 ppm to upwards of 1000 ppm. Common readings are 100 to 400 ppm. So for sake of discussion, let's say your tap water reads 400 ppm. That means that for every million parts of water, you have 400 parts of dissolved solids. How do we go about getting that TDS reading down to somewhere near zero?

If you do some experimenting with your TDS meter, you'll note that your sediment filter and carbon block do very little to remove dissolved solids. So with your tap water at 400 ppm, you can measure the water at the “in” port on your RO membrane housing and you'll see it is still approximately 400 ppm.

The RO membrane is really the workhorse of the system. It removes most of the TDS, some membranes to a greater extent than others. For instance, 100 gpd Filmtec membranes have a rejection rate of 96% (i.e., they reject 96% of the dissolved solids in the feed water). So the purified water coming from your 100 gpd membrane would be about 16 ppm (a 96% reduction). Filmtec 75 gpd (and below) membranes produce purified water (a.k.a. “permeate”) more slowly, but have a higher rejection rate (96 to 99%). The lifespan of an RO membrane is dependent upon how much water you run through it, and how “dirty” the water is. Membranes can function well for a year, two years, or more. To test the membrane, measure the TDS in the water coming into the membrane, and in the purified water (permeate) produced by the membrane. Compare that to the membrane’s advertised rejection rate, and to the same reading you recorded when the membrane was new. Membranes also commonly produce purified water more slowly as their function declines.

After the RO membrane, water will flow to your DI housing. DI resin in good condition will reduce the TDS in the RO water down to 0 or 1 ppm. When the DI output starts creeping up from 0 or 1 ppm, your resin needs to be replaced. Sometimes you'll hear people complain that their DI resin didn't last very long. Often the culprit is a malfunctioning RO membrane sending the DI resin high TDS water. This will exhaust the resin quicker than would otherwise have been the case. Sometimes the problem is poor quality resin – remember that all resins are not created equal.

Additionally, don’t forget to sanitize the entire system at least once per year, and wash and lube your housing o-rings with food-grade silicone grease every filter change.

Russ

 

[Buckeye Hydro]

Chloramine will deplete your DI faster than chlorine.

You want to know and track TDS in THREE locations:
1. Feedwater
2. RO Water
3. DI Water

In your case it may be that the RO isn't cleaning the water as well as it should. What is your RO water TDS?

What is the water pressure reaching the membrane?

Additionally, are we talking about one of those mini RO systems here? If so, that inline carbon is not a good fit for this application, especially with chloramine.